GCSE N5/A3 - integers, decimals and real numbers

This unit combines skills originally covered by Edexcel's SoW modules:

|||| Unit 2 Module 2-4 of 20

Contents: Standard form	Time: 2 – 4 hours
SPECIFICATION REFERENCE
N g	Use standard form, expressed in standard notation
N g	Convert between ordinary and standard form representations
N g	Use standard form display and know how to enter numbers in standard form
PRIOR KNOWLEDGE
Round decimals to a given number of decimal places or significant figure Multiply decimal numbers with, and without, a calculator Some experience with powers of 10, eg know that 102 = 100, 103 = 1000, 10–1 = 0.1 Negative indices and laws of indices
OBJECTIVES Lesson plans
Understand the standard form convention (5.2) Convert numbers to, and from, standard form (5.2) Round numbers given in standard form to a given number of significant figures (5.2)
DIFFERENTIATION & EXTENSION
Use standard index form in real-life situations, eg stellar distances, sizes of populations and atomic distances for small numbers
NOTES
This work can be enriched by using examples drawn from the sciences, eg Avogadro’s constant 6.02 × 10-23

A3

Algebraic formula

|||| Unit 2 Module 2-10 of 20

Contents: Formulae	Time: 3 – 6 hours
SPECIFICATION REFERENCE
Af	Substitute numbers into formulae
Af	Use formulae from mathematics and other subjects
Af	Generate a formula
	This topic is extended in Unit 3
PRIOR KNOWLEDGE
Understand of the mathematical meaning of the words expression, simplifying and formulae Experience of using letters to represent quantities Substitute into simple word expressions Using brackets in numerical calculations and removing brackets in simple algebraic expressions
OBJECTIVES Lesson plans
Use algebra or words to state the relationship between different quantities (10.2) Substitute positive and negative numbers into simple algebraic formulae (10.2) Substitute positive and negative numbers into algebraic formulae involving powers (10.2) Generate a formula from given information, eg find the formula for the perimeter of a rectangle given its area A and the length of one side (10.3)
DIFFERENTIATION & EXTENSION
Use negative numbers in formulae involving indices Various investigations leading to generalisations Further problems in generating formulae form given information Apply changing the subject to y = mx + c
NOTES
Emphasise good use of notation, eg 3ab means 3´ a ´b Students need to be clear on the meanings of the words expression, equation, formula and identity Use Functional Elements problems as a rich source of formulae given in everyday contexts Link with formulae for area, volume, surface area etc